The engineering doff mission/task to create an experimental warp core has a bug in its DOFF slots.
The first two position are required to be Matter-Antimatter Specialists, however, the 3rd and 4th slots can be any other officer, it still has the better outcome for M-A-S officers, to be assigned to it.
The problem is that it will only accept "Science" officers, and the M-A-S officers are Engineers, so you CANT, use other M-A-S officers, even if you have them, I checked and I did have more.
Comments
For example, Amsoti
When you first open the R&D ability, you also get "Emergency R&D Hologram: Matter-Antimatter Specialist" who is also a Scientist, not an engineer.
You should be able to yes, whether there are any available is another matter. That one is from a random drop from the Xindi Duty Officer (Duty Officer)] item pack which comes as a random drop from the Xindi-Amphibious Lock Box or the Infinity Lock Box.